


A Waking Nightmare

by Wingless_Hummingbird



Category: Undertale (Video Game)
Genre: First Kiss, Hurt/Comfort, Insomnia, Killer is too Curious, Love Confessions, M/M, Nightkiller - Freeform, Nightmare is a Bookworm confirmed, Nightmare x Killer - Freeform, No Smut, Past Torture, Romance, Romantic Fluff, it's complicated - Freeform, killermare - Freeform
Language: English
Status: Completed
Published: 2021-02-12
Updated: 2021-02-12
Packaged: 2021-03-12 04:09:10
Rating: Mature
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 2,502
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/29379018
Author URL: https://archiveofourown.org/users/Wingless_Hummingbird/pseuds/Wingless_Hummingbird
Summary: Killer has nightmares frequently. But after this one, he’ll finally get the one ‘nightmare’ he always wanted.Confessing their feelings doesn’t come naturally to them though. Things aren’t that simple.Let’s just see how it goes.
Relationships: Sans/Sans (Undertale)
Kudos: 50





	A Waking Nightmare

**Author's Note:**

> This pairing is just so addicting. *-* I wanted to contribute by writing a cute little confession scene. :D

_Killer is looking at a photo album he doesn’t even recollect owning, in a kitchen he’s unfamiliar with. But right now, it all makes sense to him as it is. He’s looking at old pictures of Papyrus, Grillby and another monster he somehow knows but doesn’t remember._

_Unexpectedly, it all takes a morbid direction when their faces are getting scorched and black. The skeleton screams and drops the photo album on the floor as if it burned him. Irritation sparks in his soul, but there has to be a logical explanation. Surely._

_Like remote-controlled, he walks over to the sink to splash some cold water on his face. When turning the water-tap on, a black liquid starts flowing out. Distinct scents of blood and dust fill the air around him. Immediately, he tries to turn the flow back off, but it just keeps coming, clogging the sink, soon threatening to overflow._

_“What the hell?!”, his voice rises at least one octave, and he leaps backwards. He looks around frantically, someone has to play a prank on him. A knocking on the window lets him look to the right, only to catch a glimpse of his reflection. His body freezes, Chara’s smiling directly at him instead of his mirror-image._ _ _ _

He jolts awake and gasps for air he doesn’t need, his void eye sockets filled with terror. Both hands touch his face to assure himself it was just a dream. And when feeling bones instead of skin underneath his phalanges, he exhales audibly, relieved that this demon isn’t real. It was just one out of countless crazy dreams.

After a few minutes of staring into darkness so deeply known to him, he tries to go back to sleep. But silence is a sharp razor when thoughts are a silken thread. No matter how many times he tosses and turns, he just can’t shake this dream. Which isn’t maddening per se, Killer knows what to do on nights like these.

His unhurried steps get muffled by the long carpet on the corridor as he makes his way to his boss. When it’s quiet like this, he can hear the crisp sound of several knives hidden in places not even the god of negativity himself could think of.

This habit of seeking out Nightmare after, heh, _nightmares_ developed over time. At first, it was almost as unwise as looking for shelter inside the eye of a hurricane. But Killer knows better nowadays. The black skeleton doesn’t mind his presence, frequently lets him stay and -occasionally- fall asleep after one hour or two.

Killer pushes the huge door open to find solace in the most majestic place in the whole multiverse, Night’s throne room. Usually, said skeleton would either sit on his throne or work in his study next door. His grin widens subconsciously as he thinks about his boss’ handwriting that’s borderline calligraphy or the relaxed look on his face whenever he’s reading…

But all those plans crash the second he notices that the usually locked door to Nightmare’s library is wide open. He glances around quickly, but nobody’s here. What a tempting coincidence… After a brief debate with himself whether he should walk inside or not, he shrugs. Curiosity gets the best of him; Killer isn’t known for his discretion after all. If boss leaves the door open, he surely won’t mind.

Despite his determination, walking towards the door feels like an eternity, the fear of getting caught is creeping up his spine. Could this be a test, or even a trap? But before he can reconsider his decision, he steps into the library. Welp, too late to turn back now.

The sneaky skeleton had no idea how intimidating a room filled with books can be. Rows upon rows of bookshelves, appearing like a maze, greet him. One might get claustrophobic here. Did Night read all the books in here? He slowly walks between lines of huge walls of books, without any sense of direction. A golden imprint on one shelf says ‘History Of Soul Traits’. Sounds definitely like something his boss would read.

After he passes the first lane, this place opens up significantly. There’s a comfortable-looking sofa in the shape of a crescent in the middle of this free space, enveloped in bright artificial light. The oval table in front of the sofa brings this cozy spot to perfection. Judging by a half-empty cup and books sitting on the table, his boss was here recently.

When Killer picks one randomly, his permanent grows impossibly wider, knowing he just hit the jackpot. Whenever he finds hints of Nightmare’s pre-incident life, the secretive god merely tells him it’s nothing of importance or long forgotten or something. Such a hypocrite, obviously loving history but at the same time trying to forget his own past.

Of course, Killer knows the basic story. Given that Nightmare normally doesn’t seem to be affected by anything, this is almost enticing. He turns a few pages with growing interest. It’s written like a diary, but judging by the handwriting, two individuals were writing in this book. Heh, good thing he has no sense of guilt or shame for reading it. He starts with the last page.

\------------------------------------------------------

_Greetings my little Daydream,_

_I apologize for not writing to you sooner. No need to worry, I’m fine. These rude people chose to ignore me for the time being… I fail to understand why you would think so highly of them. What do you see in them that I cannot? I am still convinced they are not trustworthy… Nonetheless, it has overall been very uneventful days. I hope you enjoy the trip, brother. I will see you in two days._

_\------------------------------------------------------_

_Hello my dearest Moonlight,_

_finally, I received a message from you! Maybe they stop their misbehavior for good. But to be honest, you don’t do much to improve your relationship with the citizens. You need to come out of your shell a bit more, brother. They have good in them, some of them are just not very good at showing it. I promise I’ll talk to them again when I return. See you tomorrow. I love you._

\------------------------------------------------------

“Rude.”, Nightmare is standing behind him, a tentacle is snatching the book out of his hands. Killer yelps and spins around quickly. How did he not notice him coming?

The silence that follows is bleak, like frozen leaves under a pile of snow. Killer feels coldness burying its way into his marrow. It’s unpleasant, yet he ~~wants to~~ can endure this. This is Nightmare’s winter; just waiting for a warm breeze. And for some reason, he wants to be this breeze for a while now.

Nightmare arranges the books on the table with an unreadable expression. Shit, Killer really shouldn’t have done that. “Come on, boss. Don’t be so _shelfish_. I wish you would _open up_ to me.”, he starts the conversation unconcerned, but prepares to get punished. Nightmare glances at him before sitting down on the sofa wordlessly.

Well, his boss hasn’t kicked him out yet. He might as well push his luck a bit more. So, Killer sits down beside him, unaffected by the other’s unapproachable aura. But this silence is quickly growing into something much worse than punishment. No matter how hard Killer tries to look somewhere else, his gaze keeps sliding back to Night.

“Boss… Fine, I’m sorry. I crossed a line there. But…”, his mind goes blank. But what? There’s no way of telling the god of negativity about his intentions. His emotions are embarrassing enough at the moment.

Nightmare sighs heavily. “Your curiosity is understandable… ‘Daydream’ never suspected that his brother was lost. ‘Moonlight’ himself believed he could win this internal battle. How foolish. I am not angry at you for reading this, the monster to whom it belonged already died.”, he explains nonchalantly, but tentacles are flicking back and forth tensely.

Killer can easily see through this charade. If it doesn’t bother him, then why does he keep this diary-style book on the table? “Welp, keeping stuff from your past makes sense. I’d love to have something like that, to remind myself what a jerk I was back then.”, he says and looks down at his target-shaped soul. The monster he once was seems to be a complete stranger now. Sans. That’s not his name anymore.

When looking back up, he notices Nightmare staring intrigued at him. The dark skeleton can see right through his soul, that’s for sure. But what exactly does he sense right now, that makes the god smile so inexplicably? Killer has to hold himself back from inching closer. This skeleton is like a black hole, his gravity is nearly irresistible.

Nightmare lifts his right hand warily. “Whenever I reach out for life…”, his fingers ghost Killer’s cheekbone, “I can feel it breaking apart.” Thanks to Killer’s quick reflexes, he puts one hand over Nightmare’s, forcing the other to cup his cheek. “Then break me, I don’t care. You saved me, I owe you my life, it is yours to take.”

The determination coming from Killer draws a chuckle from Nightmare. “I am aware of that. However, I want to be so much more than your savior…” Killer tilts his head to the side, liquid hate dripping from one eye socket and spilling over their hands. “And what would that be?”

Night turns his head away, frowning in concentration as if to find the right words. “…I wish to be pure like Dream or drown in insanity like Infected; and yet I’m nothing more than an immortal creature that always wants what it cannot get. I want to understand the world…”, he motions at the sheer endless amounts of books, “…and don't even understand my own feelings.”

He tries to pull his hand away, but Killer holds onto it. “You’re the god of negativity, but also so much more. If you could only see yourself from my perspective… I mean… If you gave me a chance, I could show it to ya. Heh, you know me, I wouldn’t mind pain.” Stars, what has gotten into him?!

Instead of jerking his hand away forcefully, Night places his second hand on Killer’s other cheek. An array of emotions washes over the black skeleton. So close, yet so far away. “Everyone thinks it will all get better eventually, so they are willing to endure pain. But for me, all hope is in vain. My craving for negativity will never cease.”, he leans closer and whispers, “How could someone like myself possibly ‘love’?”

Nightmare’s low voice sends a shiver down Killer’s spine so intensely, that he rises from the sofa. His bones are shaking, why does his soul have to act up in the most inappropriate situations?! He’s supposed to be his right hand, a steady force instead of a bucket of awkward feelings he has no names for. “I don’t get it, boss. You always take what you want. Why so hesitant?”

Night also stands up, just a bit more deliberately. “Because I have never been so conflicted about anything in my life before. You are important to me, that is why I cannot just give into my desires.”, he answers composed, but his tentacles are stiff, betraying his calm manner.

“You worry too much. Remember, I do what I’m supposed to, and you do what ya want to.”, Killer smirks when he sees Nightmare’s worried look turning into a grimace. “You never fail to surprise me, recalling my words through all the pain and suffering. I used to say these words whenever I punished you.”, Night looks sideways but can’t bring himself to regret this necessary treatment.

“Yeah, got punished enough times to make it stuck. I won’t disappoint you, that’s a promise.”, Killer’s promise lingers between them like an open present. He feels his cheekbones are heating up. Why is he important to Nightmare? What’s so special about him? Killer never had problems with a low self-esteem, but these questions haunt his mind for a while now.

When sensing the other’s emotions, Nightmare smiles reluctantly. But Killer’s right, what kind of god would he be if he cannot stand by his own words? A tentacle pushes the other closer. It’s just a gentle nudge but Killer closes the gap between them immediately.

A jolt of emotions rushes through their bodies as they kiss chastely. Nightmare leans his slightly smaller frame against the other. Neither of them has ever noticed that Killer was indeed a bit bulkier. But impressive appendances make up for that.

Killer wraps his arms around the other, and Night returns the gesture with only a brief moment of hesitation. The way all four tentacles lower submissively makes the usually emotionless skeleton way too excited for this rather innocent gesture. He pulls back to look at his god’s face, because unlike the other, he can only guess how Nightmare feels.

But apparently, he’s comfortable being held like this. Killer kisses him again, more passionate this time. For the first time, they can taste each other’s magic as their tongues intertwine lovingly. The world around them blurs into insignificance.

Even though this may count as one of the best moments of Killer’s life, he tries to suppress his positive emotions as best as he can. He doesn’t want to ruin the moment for his counterpart.

But for once, Nightmare doesn’t mind. It’s not weakening him heavily. Maybe even the god of negativity can indulge in his affection. He’d endure eternal pain if they could stay just a few moments like this. Together.

After they pull back again, Nightmare rests his skull on Killer’s shoulder. He can’t deny the feeling in their souls any longer. This particular set of emotions, which he sensed too many times in other monster’s souls, that’s undoubtedly love.

Killer’s embrace tightens. “Sorry, couldn’t resist.”, his low voice vibrates against Nightmare’s skull.

Nightmare shakes his head. “No, this was perfectly fine. I feel the same way.”, in the very moment he says these words out loud, panic bubbles in his soul. He never planned to fall in love. This is such a glaring weakness for a god like him. And highly dangerous for Killer, too.

At first, Killer is positively surprised but doesn’t worry much. He snickers as he observes the black tentacles twitching. His boss is either angry or confused. “We don’t have to be like this if you don’t want to. You’re the boss, use me as you wish.”

These words let Nightmare raise his head again. His right hand knows how to push all the right buttons. There is no way he’s gonna let him go now. “I love you, Killer.”

Killer forgets to breathe for a moment. That was unexpected. “Love you too, Nightmare… And by all goddamn stars, I’ll make sure to annihilate any enemy of yours, ‘cause you’re finally mine.” 

They sit down on the crescent sofa, holding each other as close as possible. And no nightmares or doubts could ever taint their thoughts tonight.


End file.
